I need urgent help with this. P1 support has no clue for the moment (since august 4th).
When tethered, C1 recently started to give me "failed to load image" errors after the first image which goes through normally. Restart, and one more image... Restart Camera + C1... Nothing helps.
I tried: new session, shoot with or without CF card, new cables, reinstall C1 Pro and even reinstall Windows (yes, this is really very important).
5DMk2 -> C1 pro / Win7 x64
Don't know what to do, but use the horrible Canon software or Lightroom without ICC profiles...
PS.: It might be that it all started with the last update, don't know for sure.
I had the same issue. 6.2.2 is broken on Win7-64. Open a case with phase one and they will send you a registry key patch that disables C1's hooks into WIC for the time being and that will clear it up. Or look on their forums for a download link. You could try downgrading to 6.2.1, but you will still want to run the registry patch as uninstalling 6.2.2 doesn't appear to remove the hooks.